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S. E. JOHANNESEN. Reissuedhhe 22 1920 men vouhci mnsronnzn.

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APPLICATION FlLiD KAY 18, J92!)- W H fi l g I 8 I Ev g Inventor: Svend E.Johan nesen,

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S. EJOHANNESEN,

man VOLTAGE. TRANSFORMER.

mEETHIIEET 3.

Reissued June 22. 1920.

APPUCATiOI FILED KAY 18. 1920' Fig. 1:5.

Fig. l4.

. Ihventor: Svehd E. Johannesen H His fltlofne ag UNITED sTAT s SVEI ID E. JOHA NNESEN; 0F PZETTSFIELD, MASSACHUSETTS, ASSIGNOR. T0 GENERAL I ELEQTRIC COMPANY, A CORPORATION OF NEW YORK.

HIGH-VOLTAGE TRANSFORMER.

Specification ot Reissued Letters Patent. Reissued June 22" 1920, Original No. 1,337,915, dated April 20, 1920, Serial No. 244,836,.fi1ed Ju1y 15, 1918. Application for I reissue filed May 18, 1920. Serial No. 382,694.

T 0 all whom it may concern Be it known that I, SvnNn E. JOHAN- NnsnN, a citizen of the United States, resid ing at Pittsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in High-Voltage Transformers, of which the following is a specification.

My invention relates to transformers, some reactances, and like electrical apparatus and has for its objects an improved construction and arrangel'nent of parts where by such apparatus may be more economicall manufactured.

y invention is particularly applicable to shell-type transformers but may alsobe applied to core-type transformers and is signed to afford a more efficacious manner of constructing, mounting and ventilating the windings than has heretofore been known.

In shell-type transformers, as heretofore generally constructed, the coiled conductors comprising the windings were supported in press-board casings which were in turn supported by the core; the assembled core when clamped together being anchored to a suitable base. In this construction barriers of insulating material were necessarily inserted between the coils to provide the necessary resistance to puncture, creepage, etc. Such floarriers, however, reduced the ventilating passages and consequently the full-load capacity of the transformer, the alternative construction-being an increase in the wind .ing space with a corresponding decrease in the space-factor, together with an increased tendency for the'windings to sag.

In the practice of my invention these difliculties are avoided by reason of my novel construction of the coils, in which both ade- (llltttc 1115111911011 and ventilation are pro vided without the use of barriers, the windlugs being supported independently of the core.

In. my new construction, the windings are so arranged. that the potential drop,between portions of the windings is relatively small so that little insulation is needed between turns and such portions. As a consequence I insulate the windings in groups, a plurality of associated groups preferably being incased together in an insulating jacket of high dielectric strength; such jacket being casing (not shown) the nature and objects of my invention,

reference should be had more accompanying drawing in which Figure 1 is a perspective View showing the core and coils of .a transformer embodying my invention in assembled relation; Fig. 2 is a vertical section through the transformer in the plane of the coils, the lower part being. broken away; Figs. 3, 4 and 5 are fragmentary sections taken on the lines 3.-3, 4+4 and 5-5 respectively in F ig; 2; Figs. 6 and 7 are detailed views showing the manner of connecting the leading-in conductors to the windings; Figs. 8, 9 and 10, show, in diagrammatic fashion different schemes for arranging the coil groups in transformer windings constructed in accordancewith my 1nvention; Fig. 11 is a top plan View of the arrangement of windings shown in Fig. 1, while Fig. 12 shows a plan view of a modified'arrangement; Fig. 13 shows a corestype transformer partly in elevation and partly in section, which has a cylindrical winding embodying my invention; and Fig. 14 is a section talien on the line 7-7 in Fig. 13.

Referring 'now to the drawings, and to Fig. 1 in particular, 10 representsthe core of laminated magnetic material suitable for ashell-type transformer, in the windows of which core are secured the coils 11 which are protected from the core laminations by the insulating boxing 12. The boxing 12 is spaced both. from the windings and the core as indicated in Fig. 2 in order to provide inner and outer ventilat ng passages13 and 14 respectively.

I will now describe in detail the structure of coils .11 which are supported in position, not by the core, but by" bolts '15 which are passed through. a suitable insulating structure in the corners of each of the coils and are made fast in the frame or which. supports the core 10. 5

The coiled electrical. conductors '16 (see Fig. 3) which compose the coils 11 are wound in groups a, b, c, d,"'each groupbeing composed of a convenient number of turns.

strap which is covered by one or more cov- 'The conductors 16 are preferably copper erings of cotton, silk or other insulating material; the groups'when formed being varnished or otherwise treated to render them impervious to water and moisturcf The groups a, b, c, d. are assembled in concentric relation in a plane. the spaces between the groups bein; maintainedhy a plurality of cylini'lrical insulators 1T fin-med with reduced ends as clearly indicated in Fig. 3. 1

At the inner and outer edges of an assembled group a, 0,1, r], I employ an insulating member 1h with rounded edges which serves not only to determine the contour of the finished coil but also as a base through which the bolts 15 are, passed.

A finished coil has a plurality of associated groups a, I), c. (J and rt", 2), a, a", assembled in spaced relation in two planes, one on each side of the insulating spacers 17 and l8, the whole being enveloped with a plurality of layers of insulating material 19. such material preferably consisting ot' fuller board tapered back with cheese cloth where very high voltages are used, and

muslin for the lower voltages. the Whole being varnished and treated to form a substantially solid insulatin iacket.

In order to provide ventilation for the interior of a coil constructed in this man Her, I cut comparativelv unrestricted slots, such shown at 20, in both, the top and bottom edges of the insulating jacket.

The bolts 15, which support the coils. must also be well insulated and are preferably themselves constriu-tmi of insulating material, the substance known to the trade. as micarta answering well this purpose. The proper spacing of the coils ll along the bolts 15 is insured by insulating sleeves or bushings 21 which are slipped over the bolts 15 but abut against the coil structure as shown in Fig. 4, the whole being secured by suitable nuts 22 which engage with the threaded extremities of the bolts 15.

v The electrical connections between groups (1 b, 0, rl, etc.,' in the interior of a coil are made in. such a manner as to occasion the least possible strain on the insulation, one

mode being shown in Figs; (F and 7 and diagrammatically shown in Fig. 8, alternative modes being shown in l igs. 1nd it).

In order that the connections shown in Fig. (3 maybe more clearly understood, I shall assume that the left-hand and associated right-turgid groups a, I), (Z and a. 7/, (1, (l' respectively compose a coil across whose terminals 40,000 volts is to .be impressed. .Consequently there must he a ditference in potential of 5000 voltsmcross the conductors of each of the eight groups To diminish the electrostatic strain in the interveiling dielectric for the groups, I connect the last turn in group a to the first turn in group'a', its last turn being connected to the first turn in group b and so on until we come to the last turnot' group 15. From.

the first turn of group a to the last-turn of group J, lllltl" is to be a difference in 'potential of 40,000 volts, to which turns the leading-in taps 25 and 26 are connected. This arrangement is convenient because the dili'erence in potential between the first and last turns of any two groups is onlyoUlN) volts; that is, between the first turn of (a and the first turn of rt there is 5000 volts, and between the last turn of a and the first turn oi 0 there is 5000 volts and so on. By this arrangement the lead 25 does not pass adjacent any conductor of a'grcater potential ditl'erence than 5000 volts so that its insulation is a comparatively simple matter; while the other lead 26 which connects with the innermost turnot' group J is led straight out through the coil as shown, or it may be led over the outside and may readily be insulated as heavily as desired, especially adjacent the conductors in groups and a These connections tor the groups a, a, I), b, etc.., and the manner of connecting the leads and 26am indicated in Fig. 8.

An. arrangement in which the relatiye arrangement of groups (5" and 0, c has been interchanged is shown in Fig. I, while i Fig. 10 shows an arrangement in which the groups a, Z)", c", 0 which correspond to groups a", Z 0', (Z in Fig. 8, are connected in inverted order; that is the turns progress from inside outward instead of from outside inward Still other arrangements will occur to those skilled in the art.

The primary and secondary coils for my improvedtransformer are constructed substantially si lair asahove' described except that the size and. iber oi cranium-tors in each group comp i mined by the :a raustormation.

in an assembie 'rianstormer the primary and secondary coils may be interleaved as indicated at l and S in Fig. ll. or all the coils it of either kind may be grouped together. This latter arrangement is of par ticular advantage for the high voltage coils, which group a whole may be enshrouded in an insulating jacket shown at 2? in Fig. 12. v

The jacket in. this instance, is not only provided at top and bottom with slots registering with 20 in coils ll to admit the circulation of a cooling and ventilating medium to the interior of thocoils ll. but is provided in addition with slots at top and bottom admitting the cooling and ventilating medium to the spaces between the coils ll A shell-type transformer, constructed in this manner. is very rugged and requires a smaller number of parts than has heretofore been used in their construction, the jacket of fuller board and cheese cloth providing adequate insulation for the windings from each other and from ground, where very high voltages aroused, a jacket of muslin, treated.

and varnished being sufiicient for the lower voltages. The provision of openings at the top and'bottom "of each coil, for admitting the cooling and ventilating medium (which may be oil, air, or othermedium) to pass freely over one entire surface of an sembled winding, insures a rapid and uniform dissipation of the heat from the wind ing.

"While I have shown and described my-invention in the above as applied to shell-t pc transformers, it is by no means (ZOIlilllQt to this type for I have contemplated using it conductors c, e, f, ,7, etc.

such as shown at 32, are preferably arranged jacket being in connection with core-type transformers using any suitable known type of winding; one embodiment thereof being shown in Figs. 13 and 14 which I will now describe.

In these figures, 30 denotes a core having a cylindrical coil 31 surrounding and suit' ably spaced from one leg of the core 30.

The coil 31 comprises inner and outer superimposed concentric groups of coiled Radial spacers,

1n superimposed staggered relation to insure the proper spacing of the groups. The assembled. groups have annular end spaces 32 formed to give a rounded edge to the cylindrical coil, the whole being secured together by the insulating jacket 33.1 The jacket 33 has openings 35 cut in its top and bottom edges so that the cooling and ventilating medium is freely admitted to the space between the concentric groups of coiled conductors, passing over one entire cylindrical surface of each winding to quickly absorb and dissipate the heat from each winding.

A completely assembled transformer, such as I have shown in Fig. 13, would have one or more suitably connected cylindrical coils 31 surrounding each leg thereof.

Having now described wnat is at present the best means known to me for carrying out an embodiment of my invention, I would have it understood that such means are merely illustrative and that-I do not mean to be limited thereby to the exact details'shown nor inthe choice of recognized equivalents except as'defined in. my claims hereunto ap pended. 71 i What I claim as new and desire to secure by Letters Patent of the United States, is;-

1. In a transformer, the combination with a core, of a coil comprising a plurality of as sociated groups of coiled conductors, insulating spacers formaintaining said groups in a predetermined spaced relation and an insulatmg acket enveloping said groups, said rovided with unrestricted openings for a mitting a cooling and venti lating medium to circulate; between said'.'

groups and over the edges of-said conductors.

In a transformer, the combination with a core, of a coil comprising a plurality of -associated groups of coiled coiuluctors, in-.

sulatings'pacers for maintaining said groups in a predetermined spaced relation, the spacers at the bounding edges of said groups being shaped to give the coil a desired con 'tour, and an insulating jacket enveloping said groups, said jacket beingprovided with unrestricted openings for admitting a cooling and ventilating mdiui'n to circulate be-' tween said conductors.

3. In a transformer, the combination with a core, of a coil comprising a plurality of associated groups of coiled conductors, insulating spacers for u'iaintaining said groups in a predetermined spaced relation, the spacers at the bounding edges of groups being shaped to give'the coil rounded edges,

groups and over the edges of said coil supporting bolts passing through the edge spacers, and an insulating jacket enveloping said groups, said jacket being provided with unrestricted openings for admitting a cooling and ventilating medium to circulate between said groups and over the edges of said conductors.

4. In a transformer, the combination with a core, of. a coil comprising a plurality of associated groups of coiled conductors, insulating spacers for maintaining said groups in a predetermined spaced relation, said groups having electrical connections between end turns so arranged that the potential ditt'ercnce between adjacentportions of said groups is not greater than a predetermined fraction. of the potential difference across 'the coils terminals, and an insulating acket' enveloping said groups provided with unrestricted ventilating openings.

5. In a transformer, the combination with a core, of a coil comprising a plurality of associated groups of coiled conductors, in

sulating spacers for maintaining said groups in a predetermined spaced relation, terminals for said coil, one being connected in series with an outermost turn of the connccted groups, the other being connected to an innermost turn and led straight out of the coil traversing the space between said groups, and an insulating jacket enveloping said groups provided with unrestricted ventilating openings. b. In a transformer, the combination with a shell type core, of a coilstructure composed of a plurality of units comprising windings and an insulating structure, supporting bolts passing through said coil structure, and means for securing said coil units along said bolts in predetermined spaced relation.- I

7 In a transformer, the combination with supporting bolts a shell type core, of a coil structure comgaging with theextremities of said bolts to hold said coils in predetermined positions along said bolts.

8. In a transformer, the combination with a shell-type core of laminated magnetic material, of a plurality of coils passing through the windows thereof, said coils comprising associated groups of conductors concentrically arranged in planes spaced apart and having insulating spacers about the edges thereof, supporting-bolts passing through the spacers on the outside edge of said coils, and means for securing said coils along said bolts in a predetermined spaced relation.

9. In a transformer, the combination with a core of laminated magnetic material, of a plurality of coils passing through the windows thereof, said coils comprising associated groups oi conductors com-cntrically arranged in planes spaced apart and having insulating; spacers about the edges thereoi' passing through said spacers, an insulating jacket en vcloping each coil and provided with unrestricted ventilating openings, and means for securing said coi s along said bolts in a predetermined spaced relation.

10. In a transformer, the combination with a core of laminated magnetic material, of a )lurality of coils passing; through the indows thereof, said coils comprisin; sociated groups of conductors cmu'ent'rically arranged in planes spaced a part and having insulating spacers about the edges thereof,

means for securing said coils along said belts in a predetermined spaced relation, an in sulating jacket enveloping: each coil and provided with ui'ircstrictcd ventilating openings and an additional insulating jacket enveloping a group of coils having ventilating open ings in register with the mentioned ognrniugs and additional opcnin communicating with the spaces'hctwecn said coils.

11. in a transformer. the combination with a core of laminated magnetic material, of coils composed of associated groups of coiled conductors arranged conc'cntrically in plancs in spaced relation. ano an insulating jacket for each coil provided with openings in the top and bottom cdgcsx l2. in a traustormczythccombination with a core of laminated magnetic mate'riah of coils composed of associated groups oi? coiled "crmductors arranged ctuu'eutrically in planes 'in spaced relation, supporting bolts passing through said coils. means for securing said coils along said bolts in a predetermined spaced relation, anii'isulating acket for each coil provided with openings in the top and bottom edges, and an additional jacket enveloping a group of coils having openings in register with the first said openings and additional openings communicatlng with the spaces between said coils.

- 13. A coil of winding for electrical apparatus comprising a plurality of associated groups of coiled conductors, insulating spacers for maintaining said groups in a predetermined spaced relation and an insu- .lating acliet envelopmg said groups, said jacket being provided with unrestricted openings for admitting a cooling and ventilating medium to circulate between said groups and over the edges of said conductors.

14. A coil of winding forelectrical apparatus comprising a plurality of associated groups 0. coiled conductors, insulating spacers for maintaining said groups in a predeterminedspaced relation, the spacers at the bounding edge's of said groups being shaped to give the coil a desired contour, and an insulating jacket enveloping said groups, said jacket being provided with unrestricted openings for admitting a cooling and ventilating medium to circulate be tween said groups and over the edges of said conductors.

15. A coil of winding for electrical apparatus comprising a plurality of associated. groups of coiled conductors, insulating spacers for maintaining said groups in a predetermined spaced relation, the spacers at the bounding edges of groups being shaped to give the coil rounded edges, coil supporting bolts passing through the edge" said groups and provided with diametrically opposite unrestricted ventilating openings communicating with the space between the planes of said groups.

17. A coil of winding for electrical apparatus comprising a plurality of associated groups spacers for maintaining said groups'iu a predetermined spaced relation, each of said groups being formed with a plurality of turnsgof an insulated-flat conductor, said groups being arranged in parallel planes spaced apart and connected in mries so that of coiled conductors, insulatingthe difference in potential between adjacent portions of said groups is not greater than a. predetermined traction otthe potential across the coils tern iinals, and an insulating jacket enveloping said'groups hugging the exterior surfaces oi? said groups and p 'o\'idcd with diametrically opposite unrestrictcd ventilating opei'iings communicating with the space between the planes of said groups. i

1h. A coil of winding tor electrical apparatus crnnprisiug a plurality ofassociated groups of coiled conductors, insulating spacers to]: maintaining said groups in a n-mleteriniued spaced relation, each of said tin-in,- of an insulated lint conductor, said groups being arranged in parallel planes spaced apart and connected in series, one terminal of the coil being connected to the outermost turn of one of the outer groups, the otlun-terininnl being connected to the innermost turn of an inner group and insulated along that portion extending adjacent other groups, and a ventilated insulating their outer surfaces.

.1 f A coil of winding for electrical apparatus comprising a plurality of associated groups of coiled condiwtors, insulating s nurers l'or lllillilllillllll'l said groups in a predetermined spaced relation, each of said groups being Formed with a pli'nrality of turns oi? an insulated llat conductor, said groups being arrai'iged in two parallel planes groups being formed with a plurality olfjaclcet enveloping said groups and hugging spaced apart and connected in series so that the difference of potential between honiol ogous portions of two adjacent groups is a predetermined constant fraction of the coils terminal potential difference, and an insulating j aclret enshrouding said groups hugging their oulT surfaces and provided with our restricted openings in its top and bottom edges.

20. A winding for electrical apparatus comprising a plurality of associated coils in spaced relation, each coil having an individual ventilated insulating jacket, and an enveloping insulating jacket for the jacketed coils provided with ventilating openings communicating both .With the ventilating passages in the first mentioned jackets and with the spaces between said coils.

21. A winding for electrical apparatus comprising a plurality of associated flat coils, an insulating rod having spacers thereon passing through the planes of said coils for maintaining them in a ,predeter 

